public class IERerenderBug {
    public IERerenderBug(){
        //IE9 Visualforce hack
        String browserType = Apexpages.currentPage().getHeaders().get('USER-AGENT'); //gets the browser name 
        if(browserType != null && browserType.contains('MSIE')){
            Apexpages.currentPage().getHeaders().put('X-UA-Compatible', 'IE=8');
        }
    }
}